Billy Joe Saunders says he must “send a message” to rivals when he bids for a world title in a bout described as the “most important” of his career.

Saunders, 29, faces German-based Serb Shefat Isufi for the vacant WBO world super-middleweight title on Saturday.

It follows a chaotic 18 months during which Saunders gave up a world title over an adverse doping test and was fined £100,000 for a social media post.

“I had a terrible 2018 and feel my title was robbed from me,” he said.

“I jumped at this fight when it was offered and I will become a two-weight world champion. It is all fine saying I look good hitting the pads, but I have to be on my A game and send a message to the other super-middleweights.”

BBC Radio 5 Live will have full commentary of the contest from the Lamex Stadium – home of Stevenage FC – on Saturday night, with live text commentary on the BBC Sport website.

Fight for a legacy after 2018 woe

Former world champion Billy Joe Saunders says Saunders is moving into a tough weight division

Saunders appeared well positioned after an impressive win over David Lemieux in 2017 to retain his WBO world middleweight belt but last year returned an adverse drug test finding which he said was caused by a “common decongestant nasal spray”.

The case became more complex as the Voluntary Anti-Doping Association said the substance was prohibited at all times, where as under UK Anti-Doping and World Anti-Doping Agency rules, it was only banned when an athlete is in competition.

Added to the fallout from a social media video he posted that police described as “sickening”, Saunders endured a “dreadful” year owing to “stupid and juvenile” behaviour, according to promoter Frank Warren.

“When you sit with him he can be engaging and a great personality but then he has done some silly things which have not done him any justice,” Warren told Radio 5 Live.

“This year he has to make up for it. He has to get back into the reckoning.

“I watched Saul ‘Canelo’ Alvarez v Daniel Jacobs and I believe the Saunders who beat Lemieux beats both of them. I have to get him back in that position.

“We signed twice to fight Gennady Golovkin and the fights never happened for various reasons. Canelo didn’t want to fight him and he gets disappointed.

“He comes through this and he has options at middleweight and super middleweight. I think he has the potential to be one of the best boxers of his generation.

“Bill is in a position now where his legacy is down to him.”

Defining fight for an enigma

Saunders could win a world title in a second weight division

Isufi, 29, has a record of 27 wins, three defeats and two draws – but those results have not come against fighters of the same calibre Saunders has faced, meaning the home fighter starts as a 1-100 favourite with some bookmakers.

“Saunders is an enigma,” said 5 Live boxing analyst Steve Bunce. “I’m not saying this is the last chance saloon as he’s only 29 but there are not many more chances if he were to fail or look dismal. That in some ways makes this the most important fight of his career.”

The make-or-break view on the fight is echoed by former world super-middleweight champion George Groves, who told 5 Live’s boxing podcast that Saunders must become more focused.

“I wasn’t sure how Saunders would go as a pro as I think he lacks discipline at times,” said Groves.

“At middleweight he’s in a tough division and is moving up to a division which is also tough where he will be giving away natural size.

“He will have to keep his hand speed. He’s not a huge puncher but if he can let combinations go he can be concussive. But I think he has lost a lot of momentum.

“He had the Lemieux win and it gave momentum but he has kind of dined out on that since. You have to live a clean life. Ballooning up and down in weight will take years of your career, that’s a fact.”